For determining defects on a constructional element of a turbine, like, for example, a turbine blade, it is basically known to carry out an ultrasonic inspection. Such inspections, on account of the geometries which exist in the case of such constructional elements, however, are only possible to a very limited extent and are also comparatively error-prone.
So, for example, at the present time a corresponding inspection of fastening holes of finger pin roots on turbine blades is possible only after removal of the blades.